Prime Minister Benjamin Netanyahu has undoubtedly been sipping champagne these days in celebration of his successful effort to lobby Donald Trump over the Iran nuclear deal. Netanyahu’s crude interventions to change US policy had been rebuffed by President Obama, but in Trump Netanyahu found a similarly singleminded partner who cannot see the long-term security problems that rejecting the nuclear deal will surely bring. Netanyahu praised Trump’s decision by saying that “the deal actually paves Iran’s path to an entire arsenal of nuclear bombs, and this within a few years’ time.” But he has yet to say—and cannot say—how US withdrawal will change that assessment.

Trump’s rejection of the nuclear deal actually may turn out to be a serious blow to the security of Israel and the entire Middle East. First, by further embittering Iran’s relations with the US and Israel, Trump’s decision makes a military confrontation more likely than ever, whether or not Iran proceeds to reactivate its nuclear-weapon program. Iran might retaliate for Israeli air attacks inside Syria or for Mossad’s intelligence missions inside Iran—such as the one that seized documents on Iran’s past nuclear program and was used by Netanyahu (and Trump) to make the case for Iran’s untrustworthiness. Netanyahu might now believe he has US backing to attack an Iranian nuclear site—an objective he has sought for some time and which now, at a time when his administration is wracked by a corruption scandal, he might find timely to carry out.

Second, if Iran’s supreme leader does decide to restart a nuclear-weapon program, it not only would give Washington and Tel Aviv the excuse they need to attack Iran. Saudi Arabia would also be tempted to intervene on their side—and build its own nuclear weapon in the process, as its foreign minister said on CNN (May 9). The minister blamed Iran for all the troubles in the region and claimed to have the backing of the other Arab countries. Thus, we could wind up with a “Sunni bomb” to rival Iran’s and Israel’s bombs. And there’s no evidence that the Trump administration would stand in the way of Saudi Arabia’s going nuclear.

Third, we have to consider the catastrophic consequences of a US-Israel-Saudi Arabia confrontation with Iran simultaneously with ongoing fighting elsewhere in the Middle East. Syria is already the new frontier of Israel-Iran confrontation. Wars rage in Yemen, Iraq, and Afghanistan. Total destruction of cities, massive refugee outflows, use of chemical weapons, and huge civilian casualties show us what to expect from a wider regional war.

Fourth, Iran has Hezbollah at its disposal for disrupting Israeli life in the Occupied Territories. What that move would mean for Israeli-Palestinian relations, which are already badly frayed since Trump’s decision on Jerusalem, can only be guessed.

Fifth, the US pullout from the Iran deal puts it at loggerheads with European allies, who have vowed to try to save the deal. Their efforts will further isolate Israel.

In short, while Trump and Netanyahu may think they have shown great courage in pushing Iran to the wall and defying Western allies, they have actually demonstrated extraordinary, even criminal, shortsightedness. They have assumed that an Iran weakened economically and pressured externally is a welcome development. In this, they have committed two cardinal sins of strategic planning: underestimating the opponent’s will to resist, and failing to ask “what next”? And what’s next will not be a case of unanticipated consequences.